Ok. Good start. We have death as well as a creepy mystery.

"Are you really going to say that in this room?"

Too late! No backsies!

"Neighagra,"

Besides, what's the worst that could happen?

i.ytimg.com/vi/-fP-0-dEHhA/maxresdefault.jpg

Seriously, though. I know that many authors kill the spouse, but you literally did it with viagra. This almost calls for a 'Comedy' tag instead of a 'Tragedy'.

Twilight dear, WHY DID YOU SAY THE WORDS OF CURSED FORSHADOWMENT!

Twilight continued. "The next time a certain somepony teleports in here, their cutie mark will appear on the refrigerator. Okay?" Twilight's magic manipulated the ward. She walked outside and locked the door behind her. She teleported back into the kitchen. Sure enough, her cutie mark appeared on the front of the refrigerator.

I wonder what would happen if a foal without a cutie mark somehow manages into the house?
Will the refrigerator remain blank?
Will it show a black, empty space?
Will it explode?
Or will it show the foals cutie mark before the foal even gets it?

"Besides, what's the worst that could happen?"
In the room full of forbidden spell books, the candles flickered and dimmed for a moment. Shining felt the hairs on the back of his neck stand up from a cold chill running up his spine. "Are you really going to say that in this room?"

He has a point though.
I feel like at least one of the books actually chuckled...